an example of a PDF form
(272766 bytes) where depending
on the user input (max 55 char, no validation), a 2D barcode is
drawn (it should be compliant with the PDF417 norm, I used
pdf417decode [a SourceForge project whose exact URL I don't
remember] to check it for several string inputs). Note that
the implementation of the PDF417 only accepts ASCII characters
between #\Space and (code-char 127) [bounds included] and encodes
those in a naive way. This is a kind of teaser: I did NOT include
the code necessary to draw the 2D barcode because the example is
not usable enough (too slow) and the code is too ugly.

I haven't tested an HTTP/mail submit

My PERSONAL INTERPRETATION of the docs at adobe.com is that
AcroForms will not be developed further, but its successor: XFA (XML
Forms Architecture). I found the AcroForms approach easier to begin
with so that's what I did, but the usefulness of this code might be
limited